Conventionally, an image forming apparatus such as an electrophotographic copying machine uses a developer of fine particles. In such an image forming apparatus, the developer is supplied from the developer supply container in response to consumption thereof resulting from image forming operation.
As for the conventional developer supply container, an example is disclosed in Japanese Laid-Open Utility Model Application Sho 63-6464.
In the apparatus disclosed in Japanese Laid-Open Utility Model Application Sho 63-6464, the developer is let fall all together into the image forming apparatus from the developer supply container. In addition, in the apparatus disclosed in Japanese Laid-Open Utility Model Application Sho 63-6464, a part of the developer supply container is formed into a bellow-like portion so as to permit all of the developer can be supplied into the image forming apparatus from the developer supply container even when the developer in the developer supply container is caked. More particularly, in order to discharge the developer caked in the developer supply container into the image forming apparatus side, the user pushes the developer supply container several times to expand and contract (reciprocation) the bellow-like portion.
Thus, with the apparatus disclosed in Japanese Laid-Open Utility Model Application Sho 63-6464, the user has to manually operate the bellow-like portion of the developer supply container.
In the apparatus disclosed in Japanese Laid-open Patent Application 2006-047811, a developer supply container provided with a helical projection is rotated by a rotational force inputted from an image forming apparatus, by which the developer in the developer supply container is fed. Furthermore, in the apparatus disclosed in Japanese Laid-open Patent Application 2006-047811, the developer having been fed by the helical projection with the rotation of the developer supply container is sucked into the image forming apparatus side by a suction pump provided in the image forming apparatus through a nozzle inserted into the developer supply container.
Thus, the apparatus disclosed in Japanese Laid-open Patent Application 2006-047811 requires a driving source for rotating the developer supply container and a driving source for driving the suction pump.
Under the circumstances, the inventors have investigated the following developer supply container.
A developer supply container is provided with a feeding portion receiving a rotational force to feed the developer, and is provided with a reciprocation type pump portion for discharging the developer having been fed by the feeding portion through a discharge opening. However, when such a structure is employed, a problem may arise.
That is, the problem arises in the case that the developer supply container is provided with a drive inputting portion for rotating the feeding portion and is also provided with a drive inputting portion for reciprocating the pump portion. In such a case, it is required that the two drive inputting portions of the developer supply container are properly brought into driving connection with two drive outputting portions of the image forming apparatus side, respectively.
However, the pump portion may not be properly reciprocated in such a case that the developer supply container is taken out of the image forming apparatus and then is remounted.
More particularly, depending on expansion and contraction state of the pump portion, that is, the stop position of the drive inputting portion for the pump with respect to a reciprocating direction, the drive inputting portion for the pump may not be engaged with the drive outputting portion for the pump.
For example, when the drive input to the pump portion stops in a state that the pump portion is compressed from the normal length, the pump portion restores spontaneously to the normal length when the developer supply container is taken out. In this case, the position of the drive inputting portion for the pump portion changes while the developer supply container is being taken out, despite the fact that the stop position of the drive outputting portion of the image forming apparatus side remains unchanged.
As a result, the driving connection is not properly established between the drive outputting portion of the image forming apparatus side and the drive inputting portion of the developer supply container side, and therefore, the reciprocation of the pump portion will be disabled. Then, the developer supply into the image forming apparatus is not carried out, and the image formation will become impossible sooner or later.
Such a problem may similarly arise when the expansion and contraction state of the pump portion is changed by the user while the developer supply container is outside the apparatus.
As will be understood from the foregoing, an improvement is desired to avoid the problem when the developer supply container is provided with the drive inputting portion for rotating the feeding portion and also with the drive inputting portion for reciprocating the pump portion.